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Brazier F, Cornière N, Picard N, Chambrey R, Eladari D. Pendrin: linking acid base to blood pressure. Pflugers Arch 2024; 476:533-543. [PMID: 38110744 DOI: 10.1007/s00424-023-02897-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/11/2023] [Accepted: 12/11/2023] [Indexed: 12/20/2023]
Abstract
Pendrin (SLC26A4) is an anion exchanger from the SLC26 transporter family which is mutated in human patients affected by Pendred syndrome, an autosomal recessive disease characterized by sensoneurinal deafness and hypothyroidism. Pendrin is also expressed in the kidney where it mediates the exchange of internal HCO3- for external Cl- at the apical surface of renal type B and non-A non-B-intercalated cells. Studies using pendrin knockout mice have first revealed that pendrin is essential for renal base excretion. However, subsequent studies have demonstrated that pendrin also controls chloride absorption by the distal nephron and that this mechanism is critical for renal NaCl balance. Furthermore, pendrin has been shown to control vascular volume and ultimately blood pressure. This review summarizes the current knowledge about how pendrin is linking renal acid-base regulation to blood pressure control.
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Affiliation(s)
- François Brazier
- Centre de dépistage et de Médecine de précision des Maladies Rénales, Service de Néphrologie, Centre Hospitalier Universitaire Amiens-Picardie, Université de Picardie Jules Verne, F-80000, Amiens, France
| | - Nicolas Cornière
- Centre de dépistage et de Médecine de précision des Maladies Rénales, Service de Néphrologie, Centre Hospitalier Universitaire Amiens-Picardie, Université de Picardie Jules Verne, F-80000, Amiens, France
| | - Nicolas Picard
- Laboratory of Tissue Biology and Therapeutic Engineering, UMR 5305 CNRS, University Lyon 1, Lyon, France
| | - Régine Chambrey
- Paris Cardiovascular Research Center (PARCC), INSERM U970, F-75015, Paris, France
| | - Dominique Eladari
- Centre de dépistage et de Médecine de précision des Maladies Rénales, Service de Néphrologie, Centre Hospitalier Universitaire Amiens-Picardie, Université de Picardie Jules Verne, F-80000, Amiens, France.
- Laboratory of Tissue Biology and Therapeutic Engineering, UMR 5305 CNRS, University Lyon 1, Lyon, France.
- French Clinical Research Infrastructure Network (F-CRIN): INI-CRCT, Vandœuvre-lès-Nancy, France.
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2
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Sanghavi SF, Swenson ER. Arterial Blood Gases and Acid-Base Regulation. Semin Respir Crit Care Med 2023; 44:612-626. [PMID: 37369215 DOI: 10.1055/s-0043-1770341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Disorders of acid-base status are common in the critically ill and prompt recognition is central to clinical decision making. The bicarbonate/carbon dioxide buffer system plays a pivotal role in maintaining acid-base homeostasis, and measurements of pH, PCO2, and HCO3 - are routinely used in the estimation of metabolic and respiratory disturbance severity. Hypoventilation and hyperventilation cause primary respiratory acidosis and primary respiratory alkalosis, respectively. Metabolic acidosis and metabolic alkalosis have numerous origins, that include alterations in acid or base intake, body fluid losses, abnormalities of intermediary metabolism, and renal, hepatic, and gastrointestinal dysfunction. The concept of the anion gap is used to categorize metabolic acidoses, and urine chloride excretion helps define metabolic alkaloses. Both the lungs and kidneys employ compensatory mechanisms to minimize changes in pH caused by various physiologic and disease disturbances. Treatment of acid-base disorders should focus primarily on correcting the underlying cause and the hemodynamic and electrolyte derangements that ensue. Specific therapies under certain conditions include renal replacement therapy, mechanical ventilation, respiratory stimulants or depressants, and inhibition of specific enzymes in intermediary metabolism disorders.
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Affiliation(s)
- Sarah F Sanghavi
- Division of Nephrology, Department of Medicine, University of Washington, Puget Sound Veterans Affairs Healthcare System, Seattle, Washington
| | - Erik R Swenson
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Washington, Puget Sound Veterans Affairs Healthcare System, Seattle, Washington
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3
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Pippalapalli J, Lumb A. The respiratory system and acid-base disorders. BJA Educ 2023; 23:221-228. [PMID: 37223696 PMCID: PMC10201398 DOI: 10.1016/j.bjae.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/01/2023] [Indexed: 05/25/2023] Open
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4
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Park M, Sidebotham D. Metabolic alkalosis and mixed acid-base disturbance in anaesthesia and critical care. BJA Educ 2023; 23:128-135. [PMID: 36960435 PMCID: PMC10028421 DOI: 10.1016/j.bjae.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/12/2023] [Indexed: 02/25/2023] Open
Affiliation(s)
- M. Park
- Te Matau a Maui Hawke's Bay, Hastings, New Zealand
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Steele AR, Tymko MM, Meah VL, Simpson LL, Gasho C, Dawkins TG, Villafuerte FC, Ainslie PN, Stembridge M, Moore JP, Steinback CD. Global REACH 2018: renal oxygen delivery is maintained during early acclimatization to 4,330 m. Am J Physiol Renal Physiol 2020; 319:F1081-F1089. [PMID: 32996319 DOI: 10.1152/ajprenal.00372.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Early acclimatization to high altitude is characterized by various respiratory, hematological, and cardiovascular adaptations that serve to restore oxygen delivery to tissue. However, less is understood about renal function and the role of renal oxygen delivery (RDO2) during high altitude acclimatization. We hypothesized that 1) RDO2 would be reduced after 12 h of high altitude exposure (high altitude day 1) but restored to sea level values after 1 wk (high altitude day 7) and 2) RDO2 would be associated with renal reactivity, an index of acid-base compensation at high altitude. Twenty-four healthy lowlander participants were tested at sea level (344 m, Kelowna, BC, Canada) and on day 1 and day 7 at high altitude (4,330 m, Cerro de Pasco, Peru). Cardiac output, renal blood flow, and arterial and venous blood sampling for renin-angiotensin-aldosterone system hormones and NH2-terminal pro-B-type natriuretic peptides were collected at each time point. Renal reactivity was calculated as follows: (Δarterial bicarbonate)/(Δarterial Pco2) between sea level and high altitude day 1 and sea level and high altitude day 7. The main findings were that 1) RDO2 was initially decreased at high altitude compared with sea level (ΔRDO2: -22 ± 17%, P < 0.001) but was restored to sea level values on high altitude day 7 (ΔRDO2: -6 ± 14%, P = 0.36). The observed improvements in RDO2 resulted from both changes in renal blood flow (Δ from high altitude day 1: +12 ± 11%, P = 0.008) and arterial oxygen content (Δ from high altitude day 1: +44.8 ± 17.7%, P = 0.006) and 2) renal reactivity was positively correlated with RDO2 on high altitude day 7 (r = 0.70, P < 0.001) but not high altitude day 1 (r = 0.26, P = 0.29). These findings characterize the temporal responses of renal function during early high altitude acclimatization and the influence of RDO2 in the regulation of acid-base balance.
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Affiliation(s)
- Andrew R Steele
- Neurovascular Health Lab, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Michael M Tymko
- Neurovascular Health Lab, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Victoria L Meah
- Neurovascular Health Lab, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Lydia L Simpson
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom
| | - Christopher Gasho
- Division of Pulmonary and Critical Care, School of Medicine, Loma Linda University, Loma Linda, California
| | - Tony G Dawkins
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom
| | - Francisco C Villafuerte
- Department of Biological and Physiological Sciences, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Philip N Ainslie
- Centre for Heart, Lung, and Vascular Health, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Michael Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom
| | - Jonathan P Moore
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom
| | - Craig D Steinback
- Neurovascular Health Lab, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
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6
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Zanella A, Langer T, Caironi P, Gattinoni L, Pesenti A. Reply by Zanella et al. to Swenson. Am J Respir Crit Care Med 2020; 202:908-909. [PMID: 32459983 PMCID: PMC7491387 DOI: 10.1164/rccm.202005-1842le] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Alberto Zanella
- University of MilanMilan, Italy
- Fondazione IRCCS Ca' Granda - Ospedale Maggiore PoliclinicoMilan, Italy
| | - Thomas Langer
- University of Milano-BicoccaMonza, Italy
- Grande Ospedale Metropolitano NiguardaMilan, Italy
| | - Pietro Caironi
- Azienda Ospedaliero-Universitaria S. Luigi GonzagaTurin, Italy
- University of TurinTurin, Italyand
| | | | - Antonio Pesenti
- University of MilanMilan, Italy
- Fondazione IRCCS Ca' Granda - Ospedale Maggiore PoliclinicoMilan, Italy
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Wall SM, Verlander JW, Romero CA. The Renal Physiology of Pendrin-Positive Intercalated Cells. Physiol Rev 2020; 100:1119-1147. [PMID: 32347156 PMCID: PMC7474261 DOI: 10.1152/physrev.00011.2019] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 11/06/2019] [Accepted: 11/12/2019] [Indexed: 12/13/2022] Open
Abstract
Intercalated cells (ICs) are found in the connecting tubule and the collecting duct. Of the three IC subtypes identified, type B intercalated cells are one of the best characterized and known to mediate Cl- absorption and HCO3- secretion, largely through the anion exchanger pendrin. This exchanger is thought to act in tandem with the Na+-dependent Cl-/HCO3- exchanger, NDCBE, to mediate net NaCl absorption. Pendrin is stimulated by angiotensin II and aldosterone administration via the angiotensin type 1a and the mineralocorticoid receptors, respectively. It is also stimulated in models of metabolic alkalosis, such as with NaHCO3 administration. In some rodent models, pendrin-mediated HCO3- secretion modulates acid-base balance. However, of probably more physiological or clinical significance is the role of these pendrin-positive ICs in blood pressure regulation, which occurs, at least in part, through pendrin-mediated renal Cl- absorption, as well as their effect on the epithelial Na+ channel, ENaC. Aldosterone stimulates ENaC directly through principal cell mineralocorticoid hormone receptor (ligand) binding and also indirectly through its effect on pendrin expression and function. In so doing, pendrin contributes to the aldosterone pressor response. Pendrin may also modulate blood pressure in part through its action in the adrenal medulla, where it modulates the release of catecholamines, or through an indirect effect on vascular contractile force. In addition to its role in Na+ and Cl- balance, pendrin affects the balance of other ions, such as K+ and I-. This review describes how aldosterone and angiotensin II-induced signaling regulate pendrin and the contribution of pendrin-positive ICs in the kidney to distal nephron function and blood pressure.
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Affiliation(s)
- Susan M Wall
- Departments of Medicine and Physiology, Emory University School of Medicine, Atlanta, Georgia; and Department of Medicine, University of Florida, Gainesville, Florida
| | - Jill W Verlander
- Departments of Medicine and Physiology, Emory University School of Medicine, Atlanta, Georgia; and Department of Medicine, University of Florida, Gainesville, Florida
| | - Cesar A Romero
- Departments of Medicine and Physiology, Emory University School of Medicine, Atlanta, Georgia; and Department of Medicine, University of Florida, Gainesville, Florida
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Redant S, De Bels D, Barbance O, Loulidi G, Honoré PM. Extracorporeal CO2 Removal Integrated within a Continuous Renal Replacement Circuit Offers Multiple Advantages. Blood Purif 2020; 50:9-16. [PMID: 32585671 DOI: 10.1159/000507875] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/13/2020] [Indexed: 11/19/2022]
Abstract
Extracorporeal CO2 removal within a continuous renal replacement therapy circuit offers multiple advantages for the regulation of the CO2 extraction. The authors review the impact of the dialysate solution, the buffer, and the anticoagulation on CO2 removal. They propose a theoretical model of the ideal circuit for the optimization of CO2 extraction.
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Affiliation(s)
- Sébastien Redant
- ICU Department, Brugmann University Hospital, Brussels, Belgium,
| | - David De Bels
- ICU Department, Brugmann University Hospital, Brussels, Belgium
| | - Oceane Barbance
- ICU Department, Brugmann University Hospital, Brussels, Belgium
| | - Ghalil Loulidi
- ICU Department, Brugmann University Hospital, Brussels, Belgium
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Abdulnour‐Nakhoul S, Hering‐Smith K, Hamm LL, Nakhoul NL. Effects of chronic hypercapnia on ammonium transport in the mouse kidney. Physiol Rep 2019; 7:e14221. [PMID: 31456326 PMCID: PMC6712239 DOI: 10.14814/phy2.14221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 11/24/2022] Open
Abstract
Hypercapnia and subsequent respiratory acidosis are serious complications in many patients with respiratory disorders. The acute response to hypercapnia is buffering of H+ by hemoglobin and cellular proteins but this effect is limited. The chronic response is renal compensation that increases HCO3- reabsorption, and stimulates urinary excretion of titratable acids (TA) and NH4+ . However, the main effective pathway is the excretion of NH4+ in the collecting duct. Our hypothesis is that, the renal NH3 /NH4+ transporters, Rhbg and Rhcg, in the collecting duct mediate this response. The effect of hypercapnia on these transporters is unknown. We conducted in vivo experiments on mice subjected to chronic hypercapnia. One group breathed 8% CO2 and the other breathed normal air as control (0.04% CO2 ). After 3 days, the mice were euthanized and kidneys, blood, and urine samples were collected. We used immunohistochemistry and Western blot analysis to determine the effects of high CO2 on localization and expression of the Rh proteins, carbonic anhydrase IV, and pendrin. In hypercapnic animals, there was a significant increase in urinary NH4+ excretion but no change in TA. Western blot analysis showed a significant increase in cortical expression of Rhbg (43%) but not of Rhcg. Expression of CA-IV was increased but pendrin was reduced. These data suggest that hypercapnia leads to compensatory upregulation of Rhbg that contributes to excretion of NH3 /NH4+ in the kidney. These studies are the first to show a link among hypercapnia, NH4+ excretion, and Rh expression.
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Affiliation(s)
- Solange Abdulnour‐Nakhoul
- Section of Nephrology, Departments of Medicine and PhysiologyTulane University School of MedicineNew OrleansLouisiana
| | - Kathleen Hering‐Smith
- Section of Nephrology, Departments of Medicine and PhysiologyTulane University School of MedicineNew OrleansLouisiana
| | - L. Lee Hamm
- Section of Nephrology, Departments of Medicine and PhysiologyTulane University School of MedicineNew OrleansLouisiana
| | - Nazih L. Nakhoul
- Section of Nephrology, Departments of Medicine and PhysiologyTulane University School of MedicineNew OrleansLouisiana
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10
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Huang R, Zhu J, Zhang L, Hua X, Ye W, Chen C, Sun K, Wang W, Feng L, Zhang J. Is ELABELA a reliable biomarker for hypertensive disorders of pregnancy? Pregnancy Hypertens 2019; 17:226-232. [PMID: 31487645 PMCID: PMC7001771 DOI: 10.1016/j.preghy.2019.06.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/26/2019] [Accepted: 06/25/2019] [Indexed: 11/15/2022]
Abstract
OBJECTIVE We aimed to examine the ELABELA levels at different stages of pregnancy among normotensive controls and women with hypertensive disorders of pregnancy (HDP). STUDY DESIGN A total of 336 blood samples of 169 women were collected from pre-pregnancy, the first, second, and third trimesters. Women were divided into the following six groups: 1) non-pregnant healthy women; 2) healthy pregnant controls; 3) chronic hypertension; 4) gestational hypertension; 5) preeclampsia; and 6) preeclampsia superimposed on chronic hypertension. ELABELA plasma concentrations were measured by human ELA Elisa Kit (Peninsula Laboratories International, Inc. USA). Kruskal-Wallis test was used to test whether ELABELA level in each type of HDP differed from that in gestational week-matched normotensive controls. MAIN OUTCOME MEASURES Hypertensive disorders of pregnancy. RESULTS In the first trimester, patients with gestational hypertension had higher ELABELA level than gestational week-matched normotensive controls [median (ng/ml): 31.9, (IQR (ng/ml): 16.3, 47.6) vs. 19.7 (13.7, 23.2), p = 0.03]. In the second trimester, the levels were 49.2 (32.2, 69.1) vs 24.0 (13.0, 32.6) (p = 0.002), respectively. The level for gestational hypertensive women in the third trimester did not differ significantly from that of normotensive women [43.8 (30.8, 62.7) vs 25.0 (12.3, 74.0), p = 0.82]. The ELABELA levels were similar between preeclamptic women and normotensive controls throughout pregnancy. CONCLUSIONS Maternal blood ELABELA levels in the first and second trimesters were elevated in women who developed gestational hypertension late in pregnancy, but the ELABELA level bears no significant relationship with preeclampsia during any stage of pregnancy.
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Affiliation(s)
- Rong Huang
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Jing Zhu
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China; Department of Obstetrics and Gynecology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lin Zhang
- Department of Obstetrics and Gynecology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaolin Hua
- Department of Obstetrics and Gynecology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weiping Ye
- Department of Obstetrics and Gynecology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chang Chen
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China; School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kun Sun
- Department of Pediatric Cardiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, China
| | - Weiye Wang
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Liping Feng
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China; Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, NC 27710, USA.
| | - Jun Zhang
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China; School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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11
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Yang OCY, Loh SH. Acidic Stress Triggers Sodium-Coupled Bicarbonate Transport and Promotes Survival in A375 Human Melanoma Cells. Sci Rep 2019; 9:6858. [PMID: 31048755 PMCID: PMC6497716 DOI: 10.1038/s41598-019-43262-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/18/2019] [Indexed: 12/27/2022] Open
Abstract
Melanoma cells preserve intracellular pH (pHi) within a viable range despite an acidic ambient pH that typically falls below pH 7.0. The molecular mechanisms underlying this form of acidic preservation in melanoma remain poorly understood. Previous studies had demonstrated that proton transporters including the monocarboxylate transporter (MCT), the sodium hydrogen exchanger (NHE), and V-Type ATPase mediate acid extrusion to counter intracellular acidification in melanoma cells. In this report, the expression and function of the Sodium-Coupled Bicarbonate Transporter (NCBT) family of base loaders were further characterized in melanoma cell lines. NCBT family members were found to be expressed in three different melanoma cell lines – A375, MeWo, and HS695T – and included the electrogenic sodium-bicarbonate cotransporter isoforms 1 and 2 (NBCe1 and NBCe2), the electroneutral sodium-bicarbonate cotransporter (NBCn1), and the sodium-dependent chloride-bicarbonate exchanger (NDCBE). These transporters facilitated 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS)-dependent pHi recovery in melanoma cells, in response to intracellular acidification induced by ammonium chloride prepulse. Furthermore, the expression of NCBTs were upregulated via chronic exposure to extracellular acidification. Given the current research interest in the NCBTs as a molecular driver of tumourigenesis, characterising NCBT in melanoma provides impetus for developing novel therapeutic targets for melanoma treatment.
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Affiliation(s)
- Oscar C Y Yang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, United Kingdom.,Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Hurng Loh
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, United Kingdom. .,Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan. .,Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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12
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Zouboules SM, Lafave HC, O'Halloran KD, Brutsaert TD, Nysten HE, Nysten CE, Steinback CD, Sherpa MT, Day TA. Renal reactivity: acid-base compensation during incremental ascent to high altitude. J Physiol 2018; 596:6191-6203. [PMID: 30267579 DOI: 10.1113/jp276973] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 09/19/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Ascent to high altitude imposes an acid-base challenge in which renal compensation is integral for maintaining pH homeostasis, facilitating acclimatization and helping prevent mountain sicknesses. The time-course and extent of plasticity of this important renal response during incremental ascent to altitude is unclear. We created a novel index that accurately quantifies renal acid-base compensation, which may have laboratory, fieldwork and clinical applications. Using this index, we found that renal compensation increased and plateaued after 5 days of incremental altitude exposure, suggesting plasticity in renal acid-base compensation mechanisms. The time-course and extent of plasticity in renal responsiveness may predict severity of altitude illness or acclimatization at higher or more prolonged stays at altitude. ABSTRACT Ascent to high altitude, and the associated hypoxic ventilatory response, imposes an acid-base challenge, namely chronic hypocapnia and respiratory alkalosis. The kidneys impart a relative compensatory metabolic acidosis through the elimination of bicarbonate (HCO3 - ) in urine. The time-course and extent of plasticity of the renal response during incremental ascent is unclear. We developed an index of renal reactivity (RR), indexing the relative change in arterial bicarbonate concentration ([HCO3 - ]a ) (i.e. renal response) against the relative change in arterial pressure of CO2 ( P aC O 2 ) (i.e. renal stimulus) during incremental ascent to altitude ( Δ [ HC O 3 - ] a / Δ P aC O 2 ). We aimed to assess whether: (i) RR magnitude was inversely correlated with relative changes in arterial pH (ΔpHa ) with ascent and (ii) RR increased over time and altitude exposure (i.e. plasticity). During ascent to 5160 m over 10 days in the Nepal Himalaya, arterial blood was drawn from the radial artery for measurement of blood gas/acid-base variables in lowlanders at 1045/1400 m and after 1 night of sleep at 3440 m (day 3), 3820 m (day 5), 4240 m (day 7) and 5160 m (day 10) during ascent. At 3820 m and higher, RR significantly increased and plateaued compared to 3440 m (P < 0.04), suggesting plasticity in renal acid-base compensations. At all altitudes, we observed a strong negative correlation (r ≤ -0.71; P < 0.001) between RR and ΔpHa from baseline. Renal compensation plateaued after 5 days of altitude exposure, despite subsequent exposure to higher altitudes. The time-course, extent of plasticity and plateau in renal responsiveness may predict severity of altitude illness or acclimatization at higher or more prolonged stays at altitude.
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Affiliation(s)
- Shaelynn M Zouboules
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Hailey C Lafave
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | | | | | | | - Cassandra E Nysten
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Craig D Steinback
- Faculty of Kinesiology, Sport and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | | | - Trevor A Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
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13
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Frische S, Chambrey R, Trepiccione F, Zamani R, Marcussen N, Alexander RT, Skjødt K, Svenningsen P, Dimke H. H +-ATPase B1 subunit localizes to thick ascending limb and distal convoluted tubule of rodent and human kidney. Am J Physiol Renal Physiol 2018; 315:F429-F444. [PMID: 29993276 DOI: 10.1152/ajprenal.00539.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The vacuolar-type H+-ATPase B1 subunit is heavily expressed in the intercalated cells of the collecting system, where it contributes to H+ transport, but has also been described in other segments of the renal tubule. This study aimed to determine the localization of the B1 subunit of the vacuolar-type H+-ATPase in the early distal nephron, encompassing thick ascending limbs (TAL) and distal convoluted tubules (DCT), in human kidney and determine whether the localization differs between rodents and humans. Antibodies directed against the H+-ATPase B1 subunit were used to determine its localization in paraffin-embedded formalin-fixed mouse, rat, and human kidneys by light microscopy and in sections of Lowicryl-embedded rat kidneys by electron microscopy. Abundant H+-ATPase B1 subunit immunoreactivity was observed in the human kidney. As expected, intercalated cells showed the strongest signal, but significant signal was also observed in apical membrane domains of the distal nephron, including TAL, macula densa, and DCT. In mouse and rat, H+-ATPase B1 subunit expression could also be detected in apical membrane domains of these segments. In rat, electron microscopy revealed that the H+-ATPase B1 subunit was located in the apical membrane. Furthermore, the H+-ATPase B1 subunit colocalized with other H+-ATPase subunits in the TAL and DCT. In conclusion, the B1 subunit is expressed in the early distal nephron. The physiological importance of H+-ATPase expression in these segments remains to be delineated in detail. The phenotype of disease-causing mutations in the B1 subunit may also relate to its presence in the TAL and DCT.
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Affiliation(s)
| | - Régine Chambrey
- INSERM 1188-Université de La Réunion, Sainte Clotilde, La Réunion, France
| | - Francesco Trepiccione
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Reza Zamani
- Department of Urology, Odense University Hospital , Odense , Denmark
| | - Niels Marcussen
- Department of Clinical Pathology, Odense University Hospital , Odense , Denmark
| | - R Todd Alexander
- Department of Pediatrics, University of Alberta , Edmonton, Alberta , Canada.,Membrane Protein Disease Research Group, University of Alberta , Edmonton, Alberta , Canada
| | - Karsten Skjødt
- Department of Cancer and Inflammation, Institute of Molecular Medicine, University of Southern Denmark , Odense , Denmark
| | - Per Svenningsen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark , Odense , Denmark
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark , Odense , Denmark
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14
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Romano TG, Azevedo LCP, Mendes PV, Costa ELV, Park M. Effect of continuous dialysis on blood ph in acidemic hypercapnic animals with severe acute kidney injury: a randomized experimental study comparing high vs. low bicarbonate affluent. Intensive Care Med Exp 2017; 5:28. [PMID: 28560615 PMCID: PMC5449359 DOI: 10.1186/s40635-017-0141-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/17/2017] [Indexed: 11/10/2022] Open
Abstract
Background Controlling blood pH during acute ventilatory failure and hypercapnia in individuals suffering from severe acute kidney injury (AKI) and undergoing continuous renal replacement therapy (CRRT) is of paramount importance in critical care settings. In this situation, the optimal concentration of sodium bicarbonate in the dialysate is still an unsolved question in critical care since high concentrations may worsen carbon dioxide levels and low concentrations may not be as effective in controlling pH. Methods We performed a randomized, non-blinded, experimental study. AKI was induced in 12 female pigs via renal hilum ligation and hypoventilation by reducing the tidal volume during mechanical ventilation with the goal of achieving a pH between 7.10–7.15. After achieving the target pH, animals were randomized to undergo isovolemic hemodialysis with one of two bicarbonate concentrations in the dialysate (40 mEq/L [group 40] vs. 20 mEq/L [group 20]). Results Hemodynamic, respiratory, and laboratory data were collected. The median pH value at CRRT initiation was 7.14 [7.12, 7.15] in group 20 and 7.13 [7.09, 7.14] in group 40 (P = ns). The median baseline PaCO2 was 74 [72, 81] mmHg in group 20 vs. 79 [63, 85] mmHg in group 40 (P = ns). After 3 h of CRRT, the pH value was 7.05 [6.95, 7.09] in group 20 and 7.12 [7.1, 7.14] in group 40 (P < 0.05), with corresponding values of PaCO2 of 85 [79, 88] mmHg vs. 81 [63, 100] mmHg (P = ns). The difference in pH after 3 h was due to a metabolic component [standard base excess −10.4 [−12.5, −9.5] mEq/L in group 20 vs. –7.6 [−9.2, −5.1] mEq/L in group 40) (P < 0.05)]. Despite the increased infusion of bicarbonate in group 40, the blood CO2 content did not change during the experiment. The 12-h survival rate was higher in group 40 (67% vs. 0, P = 0.032). Conclusions A higher bicarbonate concentration in the dialysate of animals undergoing hypercapnic respiratory failure was associated with improved blood pH control without increasing the PaCO2 levels. Electronic supplementary material The online version of this article (doi:10.1186/s40635-017-0141-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Thiago Gomes Romano
- Nephrology Department, ABC Medical School, Av. Príncipe de Gales, 821, Príncipe de Gales, Santo André, São Paulo, 09060-650, Brazil. .,Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil.
| | - Luciano Cesar Pontes Azevedo
- Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil.,Emergency Medicine Discipline, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - Pedro Vitale Mendes
- Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil.,Emergency Medicine Discipline, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - Eduardo Leite Vieira Costa
- Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil.,Cardio-Pulmonary Department, Pulmonary Division, Heart Institute (Incor), University of São Paulo, São Paulo, Brazil
| | - Marcelo Park
- Research and Education Institute, Hospital Sírio-Libanês, São Paulo, Brazil.,Emergency Medicine Discipline, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
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15
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Paulsen IMS, Dimke H, Frische S. A single simple procedure for dewaxing, hydration and heat-induced epitope retrieval (HIER) for immunohistochemistry in formalin fixed paraffin-embedded tissue. Eur J Histochem 2015; 59:2532. [PMID: 26708177 PMCID: PMC4698609 DOI: 10.4081/ejh.2015.2532] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 10/12/2015] [Accepted: 10/14/2015] [Indexed: 11/22/2022] Open
Abstract
Heat-induced epitope retrieval (HIER) is widely used for immunohistochemistry on formalin fixed paraffin-embedded tissue and includes temperatures well above the melting point of paraffin. We therefore tested whether traditional xylene-based removal of paraffin is required on sections from paraffin-embedded tissue, when HIER is performed by vigorous boiling in 10 mM Tris/0.5 mM EGTA-buffer (pH=9). Immunohistochemical results using HIER with or without prior dewaxing in xylene were evaluated using 7 primary antibodies targeting proteins located in the cytosol, intracellular vesicles and plasma membrane. No effect of omitting prior dewaxing was observed on staining pattern. Semiquantitative analysis did not show HIER to influence the intensity of labelling consistently. Consequently, quantification of immune labelling intensity using fluorescent secondary antibodies was performed at 5 dilutions of primary antibody with and without prior dewaxing in xylene. No effect of omitting prior dewaxing on signal intensity was detectable indicating similar immunoreactivity in dewaxed and non-dewaxed sections. The intensity of staining the nucleus with the DNA-stain ToPro3 was similarly unaffected by omission of dewaxing in xylene. In conclusion, the HIER procedure described and tested can be used as a single procedure enabling dewaxing, hydration and epitope retrieval for immunohistochemistry in formalin fixed paraffin-embedded tissue.
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16
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Gueutin V, Vallet M, Jayat M, Peti-Peterdi J, Cornière N, Leviel F, Sohet F, Wagner CA, Eladari D, Chambrey R. Renal β-intercalated cells maintain body fluid and electrolyte balance. J Clin Invest 2013; 123:4219-31. [PMID: 24051376 DOI: 10.1172/jci63492] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 06/28/2013] [Indexed: 12/11/2022] Open
Abstract
Inactivation of the B1 proton pump subunit (ATP6V1B1) in intercalated cells (ICs) leads to type I distal renal tubular acidosis (dRTA), a disease associated with salt- and potassium-losing nephropathy. Here we show that mice deficient in ATP6V1B1 (Atp6v1b1-/- mice) displayed renal loss of NaCl, K+, and water, causing hypovolemia, hypokalemia, and polyuria. We demonstrated that NaCl loss originated from the cortical collecting duct, where activity of both the epithelial sodium channel (ENaC) and the pendrin/Na(+)-driven chloride/bicarbonate exchanger (pendrin/NDCBE) transport system was impaired. ENaC was appropriately increased in the medullary collecting duct, suggesting a localized inhibition in the cortex. We detected high urinary prostaglandin E2 (PGE2) and ATP levels in Atp6v1b1-/- mice. Inhibition of PGE2 synthesis in vivo restored ENaC protein levels specifically in the cortex. It also normalized protein levels of the large conductance calcium-activated potassium channel and the water channel aquaporin 2, and improved polyuria and hypokalemia in mutant mice. Furthermore, pharmacological inactivation of the proton pump in β-ICs induced release of PGE2 through activation of calcium-coupled purinergic receptors. In the present study, we identified ATP-triggered PGE2 paracrine signaling originating from β-ICs as a mechanism in the development of the hydroelectrolytic imbalance associated with dRTA. Our data indicate that in addition to principal cells, ICs are also critical in maintaining sodium balance and, hence, normal vascular volume and blood pressure.
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17
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Parker MD, Boron WF. The divergence, actions, roles, and relatives of sodium-coupled bicarbonate transporters. Physiol Rev 2013; 93:803-959. [PMID: 23589833 PMCID: PMC3768104 DOI: 10.1152/physrev.00023.2012] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mammalian Slc4 (Solute carrier 4) family of transporters is a functionally diverse group of 10 multi-spanning membrane proteins that includes three Cl-HCO3 exchangers (AE1-3), five Na(+)-coupled HCO3(-) transporters (NCBTs), and two other unusual members (AE4, BTR1). In this review, we mainly focus on the five mammalian NCBTs-NBCe1, NBCe2, NBCn1, NDCBE, and NBCn2. Each plays a specialized role in maintaining intracellular pH and, by contributing to the movement of HCO3(-) across epithelia, in maintaining whole-body pH and otherwise contributing to epithelial transport. Disruptions involving NCBT genes are linked to blindness, deafness, proximal renal tubular acidosis, mental retardation, and epilepsy. We also review AE1-3, AE4, and BTR1, addressing their relevance to the study of NCBTs. This review draws together recent advances in our understanding of the phylogenetic origins and physiological relevance of NCBTs and their progenitors. Underlying these advances is progress in such diverse disciplines as physiology, molecular biology, genetics, immunocytochemistry, proteomics, and structural biology. This review highlights the key similarities and differences between individual NCBTs and the genes that encode them and also clarifies the sometimes confusing NCBT nomenclature.
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Affiliation(s)
- Mark D Parker
- Dept. of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106-4970, USA.
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18
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Jia X, Yin L, Feng Y, Peng X, Ma F, Yao Y, Liu X, Zhang Z, Yuan Z, Zhang L. A dynamic plasma membrane proteome analysis of alcohol-induced liver cirrhosis. Proteome Sci 2012; 10:39. [PMID: 22682408 PMCID: PMC3558348 DOI: 10.1186/1477-5956-10-39] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 05/25/2012] [Indexed: 12/26/2022] Open
Abstract
Alcohol-induced injury has become one of the major causes for liver cirrhosis. However, the molecular mechanisms of ethanol-induced injury are not fully understood. To this end, we performed a dynamic plasma membrane proteomic research on rat model. A rat model from hepatitis to liver cirrhosis was developed. Plasma membrane from liver tissue with liver fibrosis stage of 2 and 4 (S2 and S4) was purified by sucrose density gradient centrifugation. Its purification was verified by western blotting. Proteins from plasma membrane were separated by two-dimensional electrophoresis (2DE) and differentially expressed proteins were identified by tandem mass spectrometry. 16 consistent differentially expressed proteins from S2 to S4 were identified by mass spectrometry. The expression of differentially expressed proteins annexin A6 and annexin A3 were verified by western blotting, and annexin A3 was futher verified by immunohistochemistry. Our research suggests a possible mechanism by which ethanol alters protein expression to enhance the liver fibrosis progression. These differentially expressed proteins might be new drug targets for treating alcoholic liver cirrhosis.
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Affiliation(s)
- Xiaofang Jia
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Lin Yin
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Yanling Feng
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Xia Peng
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Fang Ma
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Yamin Yao
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Xiaoqian Liu
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Zhiyong Zhang
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Zhenghong Yuan
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China
| | - Lijun Zhang
- Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, China.,Institute of Clinical Pharmacology, Pharmacogenetics Research Institute, Changsha, Hunan 410078, China
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19
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Silva PHI, Girardi ACC, Neri EA, Rebouças NA. Distinct mechanisms underlie adaptation of proximal tubule Na+/H+ exchanger isoform 3 in response to chronic metabolic and respiratory acidosis. Pflugers Arch 2012; 463:703-14. [PMID: 22419175 DOI: 10.1007/s00424-012-1092-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 02/03/2012] [Accepted: 02/22/2012] [Indexed: 12/11/2022]
Abstract
The Na(+/)H(+) exchanger isoform 3 (NHE3) is essential for HCO(3)(-) reabsorption in renal proximal tubules. The expression and function of NHE3 must adapt to acid-base conditions. The goal of this study was to elucidate the mechanisms responsible for higher proton secretion in proximal tubules during acidosis and to evaluate whether there are differences between metabolic and respiratory acidosis with regard to NHE3 modulation and, if so, to identify the relevant parameters that may trigger these distinct adaptive responses. We achieved metabolic acidosis by lowering HCO(3)(-) concentration in the cell culture medium and respiratory acidosis by increasing CO(2) tension in the incubator chamber. We found that cell-surface NHE3 expression was increased in response to both forms of acidosis. Mild (pH 7.21 ± 0.02) and severe (6.95 ± 0.07) metabolic acidosis increased mRNA levels, at least in part due to up-regulation of transcription, whilst mild (7.11 ± 0.03) and severe (6.86 ± 0.01) respiratory acidosis did not up-regulate NHE3 expression. Analyses of the Nhe3 promoter region suggested that the regulatory elements sensitive to metabolic acidosis are located between -466 and -153 bp, where two consensus binding sites for SP1, a transcription factor up-regulated in metabolic acidosis, were localised. We conclude that metabolic acidosis induces Nhe3 promoter activation, which results in higher mRNA and total protein level. At the plasma membrane surface, NHE3 expression was increased in metabolic and respiratory acidosis alike, suggesting that low pH is responsible for NHE3 displacement to the cell surface.
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Affiliation(s)
- Pedro Henrique Imenez Silva
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 1524, sala 222, Cidade Universitária, São Paulo, SP, Brazil.
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20
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Acid-base disorders in patients with chronic obstructive pulmonary disease: a pathophysiological review. J Biomed Biotechnol 2012; 2012:915150. [PMID: 22500110 PMCID: PMC3303884 DOI: 10.1155/2012/915150] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 10/26/2011] [Indexed: 11/21/2022] Open
Abstract
The authors describe the pathophysiological mechanisms leading to development of acidosis in patients with chronic obstructive pulmonary disease and its deleterious effects on outcome and mortality rate. Renal compensatory adjustments consequent to acidosis are also described in detail with emphasis on differences between acute and chronic respiratory acidosis. Mixed acid-base disturbances due to comorbidity and side effects of some drugs in these patients are also examined, and practical considerations for a correct diagnosis are provided.
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21
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Luke RG, Galla JH. It is chloride depletion alkalosis, not contraction alkalosis. J Am Soc Nephrol 2012; 23:204-7. [PMID: 22223876 DOI: 10.1681/asn.2011070720] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Maintenance of metabolic alkalosis generated by chloride depletion is often attributed to volume contraction. In balance and clearance studies in rats and humans, we showed that chloride repletion in the face of persisting alkali loading, volume contraction, and potassium and sodium depletion completely corrects alkalosis by a renal mechanism. Nephron segment studies strongly suggest the corrective response is orchestrated in the collecting duct, which has several transporters integral to acid-base regulation, the most important of which is pendrin, a luminal Cl/HCO(3)(-) exchanger. Chloride depletion alkalosis should replace the notion of contraction alkalosis.
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Affiliation(s)
- Robert G Luke
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
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22
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Wagner CA, Mohebbi N, Capasso G, Geibel JP. The anion exchanger pendrin (SLC26A4) and renal acid-base homeostasis. Cell Physiol Biochem 2011; 28:497-504. [PMID: 22116363 DOI: 10.1159/000335111] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2011] [Indexed: 01/29/2023] Open
Abstract
The anion exchanger pendrin (Pds, SLC26A4) transports various anions including bicarbonate, chloride and iodide. In the kidney, pendrin is exclusively expressed on the luminal pole of bicarbonate-secretory type B intercalated cells. Genetic ablation of pendrin in mice abolishes luminal chloride-bicarbonate exchanger activity from type B intercalated cells suggesting that pendrin is the apical bicarbonate extruding pathway. The renal expression of pendrin is developmentally adapted and pendrin positive cells originate from both the uretric bud and mesenchyme. In adult kidney, pendrin expression and activity is regulated by systemic acid-base status, dietary electrolyte intake (mostly chloride), and hormones such as angiotensin II and aldosterone which can affect subcellular localization, the relative number of pendrin expressing cells, and the overall abundance consistent with a role of pendrin in maintaining normal acid-base homeostasis. This review summarizes recent findings on the role and regulation of pendrin in the context of the kidneys role in acid-base homeostasis in health and disease.
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Affiliation(s)
- Carsten A Wagner
- Institute of Physiology and Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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23
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Doucet A, Eladari D. [Pendrin: its role in kidney function and hypertension]. Med Sci (Paris) 2010; 26:1074-8. [PMID: 21187047 DOI: 10.1051/medsci/201026121074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Loss-of-function mutations of the pendrin gene are responsible for a pathology characterized by dysfunctions of thyroid and inner ear. However, it rapidly appeared after its discovery that the anion exchanger encoded by this gene plays a central role in kidneys. This brief review pictures the evolution of our knowledge regarding renal functions of pendrin, with a special emphasis to its recently identified roles in the maintenance of sodium homeostasis and blood pressure.
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Affiliation(s)
- Alain Doucet
- Universités Paris 5 et Paris 6, Inserm (UMRS 872) et CNRS (ERL 7226), Laboratoire de génomique, physiologie et physiopathologie rénales, Centre de recherche des Cordeliers, 15, rue de l'École de Médecine, 75006 Paris, France.
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24
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Chang RL, Xie L, Xie L, Bourne PE, Palsson BØ. Drug off-target effects predicted using structural analysis in the context of a metabolic network model. PLoS Comput Biol 2010; 6:e1000938. [PMID: 20957118 PMCID: PMC2950675 DOI: 10.1371/journal.pcbi.1000938] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 08/23/2010] [Indexed: 02/07/2023] Open
Abstract
Recent advances in structural bioinformatics have enabled the prediction of protein-drug off-targets based on their ligand binding sites. Concurrent developments in systems biology allow for prediction of the functional effects of system perturbations using large-scale network models. Integration of these two capabilities provides a framework for evaluating metabolic drug response phenotypes in silico. This combined approach was applied to investigate the hypertensive side effect of the cholesteryl ester transfer protein inhibitor torcetrapib in the context of human renal function. A metabolic kidney model was generated in which to simulate drug treatment. Causal drug off-targets were predicted that have previously been observed to impact renal function in gene-deficient patients and may play a role in the adverse side effects observed in clinical trials. Genetic risk factors for drug treatment were also predicted that correspond to both characterized and unknown renal metabolic disorders as well as cryptic genetic deficiencies that are not expected to exhibit a renal disorder phenotype except under drug treatment. This study represents a novel integration of structural and systems biology and a first step towards computational systems medicine. The methodology introduced herein has important implications for drug development and personalized medicine. Pharmaceutical science is only beginning to scratch the surface on the exact mechanisms of drug action that lead to a drug's breadth of patient responses, both intended and side effects. Decades of clinical trials, molecular studies, and more recent computational analysis have sought to characterize the interactions between a drug and the cell's molecular machinery. We have devised an integrated computational approach to assess how a drug may affect a particular system, in our study the metabolism of the human kidney, and its capacity for filtration of the contents of the blood. We applied this approach to retrospectively investigate potential causal drug targets leading to increased blood pressure in participants of clinical trials for the drug torcetrapib in an effort to display how our approach could be directly useful in the drug development process. Our results suggest specific metabolic enzymes that may be directly responsible for the side effect. The drug screening framework we have developed could be used to link adverse side effects to particular drug targets, discover new uses for old drugs, identify biomarkers for metabolic disease and drug response, and suggest genetic or dietary risk factors to help guide personalized patient care.
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Affiliation(s)
- Roger L. Chang
- Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America
| | - Li Xie
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Lei Xie
- San Diego Supercomputer Center, University of California San Diego, La Jolla, California, United States of America
| | - Philip E. Bourne
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
- San Diego Supercomputer Center, University of California San Diego, La Jolla, California, United States of America
| | - Bernhard Ø. Palsson
- Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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25
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Zhang L, Peng X, Zhang Z, Feng Y, Jia X, Shi Y, Yang H, Zhang Z, Zhang X, Liu L, Yin L, Yuan Z. Subcellular proteome analysis unraveled annexin A2 related to immune liver fibrosis. J Cell Biochem 2010; 110:219-28. [PMID: 20225235 DOI: 10.1002/jcb.22529] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
It is important to study the mechanism of liver fibrogenesis, and find new non-invasive biomarkers. In this study, we used subcellular proteomic technology to study the plasma membrane (PM) proteins related to immune liver fibrosis and search for new non-invasive biomarkers. A rat liver fibrosis model was induced by pig serum injection. The liver fibrogenesis from stage (S) S0-1, S2, S3-4, and S4 was detected by Masson staining and HE staining in this rat model after 2, 4, 6, and 8 weeks of treatment. The liver PM was enriched and analyzed using subcellular proteomic technology. The differentially expressed proteins were verified by Western blotting, immunohistochemistry, and ELISA. PM with 149-fold purification was obtained and 22 differentially expressed proteins were identified. Of which, annexin A2 (ANXA2) was detected to be increased obviously in S4 compared with S0-1, and verified by Western blotting of rat liver tissue and immunohistochemistry of rat and human liver tissue. The expression of ANXA2 in human plasma with S1-2 was also found to be up-regulated for 1.4-fold than that in S0. Furthermore, ANXA2 was detected to translocate from nuclear membrane and cytosol to PM as HBV stimulation through immunocytochemical analysis in vitro. This study identified 22 differentially expressed proteins related to liver fibrosis, and verified a potential biomarker (ANXA2) for non-invasive diagnosis of immune liver fibrosis. To our knowledge, it was the first time to dynamically study the proteins related to liver fibrosis and select biomarkers for liver fibrosis diagnosis through PM proteome research.
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Affiliation(s)
- Lijun Zhang
- Shanghai Public Health Clinical Center, Shanghai 201508, China.
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